document.addEventListener('DOMContentLoaded', function() {  
	var buttons = document.querySelectorAll('.col-4-button');  
	buttons.forEach(function(button) {  
		button.addEventListener('click', function() {  
			// 移除所有按钮的 selected 类  
			buttons.forEach(function(btn) {  
			btn.classList.remove('selected');  
			});  
					  
			// 为被点击的按钮添加 selected 类  
			this.classList.add('selected');  
			 });  
	 });  
});

document.addEventListener('DOMContentLoaded', function() {  
	var buttons = document.querySelectorAll('.col-5-button');  
	buttons.forEach(function(button) {  
		button.addEventListener('click', function() {  
			// 移除所有按钮的 selected 类  
			buttons.forEach(function(btn) {  
			btn.classList.remove('selected');  
			});  
					  
			// 为被点击的按钮添加 selected 类  
			this.classList.add('selected');  
			 });  
	 });  
});

document.addEventListener('DOMContentLoaded', function() {  
	var buttons = document.querySelectorAll('.col-6-button');  
	buttons.forEach(function(button) {  
		button.addEventListener('click', function() {  
			// 移除所有按钮的 selected 类  
			buttons.forEach(function(btn) {  
			btn.classList.remove('selected');  
			});  
					  
			// 为被点击的按钮添加 selected 类  
			this.classL6ist.add('selected');  
			 });  
	 });  
});


